I just tried my IFS-R,
it handles very well with just spring change and droop screw setting.
You don't "need" to change anything to make it a competitive car.
If there is anything you "need" to change to make your car go faster,
it might be the driver's style and skills.
Drive and explore it first,
then only change what you feel is needed.
Don't be like those people who modify just because you want to modify something
1 thing you can change on the stock IFS-R is front spool or front 1 way
because I dont like front Diff
and front spring can change to harder ones
if your plastic tub breaks, get a carbon tub
my IFS-R goes like this:
Stock with front spool and black front springs->
change to front 1 way->
plastic tub broke changed to carbon tub->
broke front arm and steel rod,changed to Titanium Rods->
pat pat itchy change to 3Racing suspension mount and Carbon Chasis and very regret...(i broke them all in 1 race)
I think the best and most cost efficient way to play IFS-R is Stock with front spool/1-way depending on the racing style
spend your money on good Servo(I got 9551) and Electronics
if the Plastic Tub breaks change to Carbon Tub for $2xx, harder and lighter
this is enough for you to beat many cars if you have good skills
people say IFS-R is not as fast as TA-05 but I have both and it is not true
IFS-R is harder to set only and you need to spend more time on the back ball diff
true
and TA-05 is a very good car in fact
IFS-R is very good and the low profile suspension makes it very interesting
in fact IFS-R uses many 415/416 parts
the point is
giving you a 416 will not give you better skill
and 416 is double the price of IFS-R
in fact for a beginner, 416 is harder to set and maintain because it has a open gear box and needs to be cleaned very often, and a slight change in setting makes the car drive very different
TA-05 is a good car out of the box
using the "manual setting" is already very easy to drive fast
IFS-R can even use low profile GT body and its very cool(and fast)
and its 50/50 distribution makes it easier to handle and set(I think so)
paying double the $$ for a 416 is ok, it is a better car and worths the money
but if you cannot bring the most out of 416, why not start with TA-05 and have some good fun with it first
I personally have a TA-05, TA-05 IFS-R, and a X-ray T2
I never thought TA-05 was a wrong decision to choose and in fact I have beated 414,415,and 416 before (of course it was driver's problem too)